Apparatus for manufacturing pipes and tubes



Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4Sheets-Sheet 1 Fig.

INVENTOR 6067A VE GR/ETEN WWW ATTORNEYS Dec. 25, 1962 G. GRIETEN3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4Sheets-Sheet 2 Fig. 9

INVENTOR GU5TAVE GR/ETEN B; gihdnm/ ATTORNEXS Dec. 25, 1962 G. GRIETEN3,070,054

APPARATUS FOR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 I 4Sheets-Sheet 3 m4 f :11 1:11 1/ i:

INVENTOR.

B GU5TA VE 'GRIE TEN Affomevs Dec. 25, 1962 G. GRIETEN 3,070,054

APPARATUS F OR MANUFACTURING PIPES AND TUBES Filed Aug. 29, 1957 4Sheets-Sheet 4 INVENTOR.

BY GUST/l VE GR/ETE/Y United States Patent Office 3,070,05 APPARATUS FORMANUFACTURING PIPES AND TUBES Gustave Grieten, Alleur, Belgium, assignorto Societe Spiralit, Liege, Beigium Filed Aug. 29, 1957, Ser. No.681,024 Claims priority, application Belgium Aug. 30, 1956 2 Claims.(Cl. 113-35) The present invention relates to a tube and pipemanufacturing machine. More in particular the present invention relatesto a machine for producing tubes or pipes from a metal sheet which ishelically rolled and welded at the adjoining rims.

In a known type of tube manufacturing machines the metal sheet is drawnby and rolled around a rotatable mandrel. Some of these machinescomprise cylindrical exterior rolls designed to force the metal sheetagainst the mandrel.

In another type of such machines, the metal sheet is helically wound bypushing the sheet obliquely into a bending device having rolls or disks.In some of the last-mentioned machines the bending is effected by makingthe metal sheet bend around a cylindrical support or an assembly ofwheels or rolls disposed inside of the tube to be formed from the metalsheet. In these cases the bending is obtained by this cylindricalsupport and two additional cylinders or rolls disposed in front of andbehind the cylindrical support, thus effecting a bending of the metalsheet. After leaving the bending device the metal sheet has assumed atubular configuration. In order to maintain the desired diameter of thetube formed of the helically wound sheet at the welding point it isnecessary to subject the two sides of the sheet to the pressure of anexterior wheel or roll. In still other machines known in the art thebending is effected entirely or partly by a substantially cylindricaljacket having a longitudinal opening through which the metal sheet isintroduced. Some of these machines have in the area where the metalsheet enters the jacket bending devices such as rolls or the like. Thesebending devices give an excess bent or curvature to the metal sheet.Consequently, the coil tends to reopen, while the casing is designed tolimit this reopening of the coil so that the tube formed of the metalsheet is supported by the walls of the jacket and is prevented fromexpanding to a diameter superior to the desired diameter of the finishedtube.

These devices and in particular the machines of the last-mentioned typehaving bending devices consisting of rolls and a bent-retaining jacketare unsatisfactory. According to the varying width of the metal sheetsand the elasticity coefficient of the metal the residual tension in thesheet at the time of the welding of the rims cannot be properlycontrolled. In order to limit such tensions the machine must be designedand operate with extreme precision. Furthermore, only a tube of a givendiameter can be produced with one of these machines, and the productionof tubes or pipes is thus rendered very complicated and costly.

In still other machines the bending devices impart a curvature having adiameter exceeding the diameter of the finished tube and the jacket isonly used to give the desired diameter to the helically wound sheet andretain this form and size of the tube until the welding has been done.In this case, too, the sheet retains uncontrolled residual tensions andone individual machine can produce only a tube of a given diameter.

In both of the last-mentioned machines, in which the jacket either hasto contribute to shape the tube or has to maintain the shape and size ofthe tube until the welding can be done, the mutual contact between thejacket 3,070,054 Patented Dec. 25, 1962 and the metal sheet produces aconsiderable friction. The metal sheet leaves the jacket with tracessuch as scratches and the like, and the casing has to be provided with alining of special steel which nevertheless is subject to wear and has tobe replaced occasionally.

It is an object of the present invention to provide a tube manufacturingmachine of the type bending metal sheets to form a helically wound coiland fixing together the adjoining rims of the helically wound sheetpreferably by welding, which is less expensive in construction andoperation than known machines.

It is another object of the present invention to provide a tubemanufacturing machine of the type bending metal sheets to form ahelically wound coil and fixing together the adjoining rims of thehelically wound sheet, which can be adapted to produce tubes or pipes ofvarious diameters.

It is a further object of the present invention to provide a tubemanufacturing machine of the type bending metal sheets to form ahelically wound coil and fixing together the adjoining rims of thehelically wound sheet, in which residual tensions of the metal sheetafter the bending are virtually eliminated or evenly and uniformlydistributed.

It is still a further object of the present invention to provide a tubemanufacturing machine of the type bending metal sheets to form ahelically wound coil and fixing together the adjoining rims of thehelically wound sheet, in which a friction between the metal sheet andthe bending device is reduced to a minimum.

It is yet another object of the present invention to provide a tubemanufacturing machine of the type bending metal sheets to form ahelically wound coil and fixing together the adjoining rims of thehelically wound sheet, which does not impair the smooth surface of themetal sheet.

It is still another object of the present invention to provide a tubemanufacturing machine of the type bending metal sheets to form ahelically wound coil and fixing together the adjoining rims of thehelically wound sheet, to provide further improvements of auxiliarydevices of the means for fixing together the rims of the helically woundmetal sheet by welding.

These objects are achieved by the present invention based on that typeof machine producing tubes by attaching to each other the adjoining rimsof a helically wound metal sheet and having means for introducing themetal sheet obliquely into a forming device. According to the presentinvention, the forming device comprises a plurality of bodies, such asrolls, rotating around parallel axes and forming in their totality asubstantially cylindrical, though not continuous, jacket, and arrangedoutside of and at least partly around the metal sheet of which the tubeis to be formed and supporting the latter.

According to a preferred embodiment of the present invention there isprovided, in addition to the plurality of exterior rolls a plurality ofinterior rolls which also rotate around axes parallel to the axes aroundwhich the exterior rolls rotate, and also forming in their totality asubstantially cylindrical, though not continuous, jacket, disposedinside of the metal sheet of which the tube is formed, these interiorrolls forming together with the exterior rolls a plurality of successivebending devices acting upon a given point of the metal sheet insuccession.

The interior and exterior rolls are preferably arranged equidistantlyfrom the next following exterior or interior roll, respectively, at thecircumference of the section of an exterior or interior imaginarycircle, respectively, and the interior rolls are so arranged relative tothe exterior rolls that in following the circumference of the interiorand exterior circles an exterior roll alternates with an interior roll.

Preferably, the exterior and interior rolls are provided with aplurality of sleeves positioned adjacent to each other on the supportshafts of the rolls with a certain longitudinal play provided betweenthe juxtaposed sleeves. Furthermore, adjusting means are provided forradially adjusting one or all of the exterior rolls relative to theinterior rolls, or vice versa.

Furthermore, the invention provides improvements of the known means forfixing together the adjacent rims of the helically wound metal sheets bywelding, consisting of automatic adjustment and control means foradjusting the position of the rims at the welding point and of means foradjusting the position and facilitating the adjustment of the supportshoe of the metal sheet at the welding point.

The invention will be more fully appreciated upon the followingdescription of the accompanying drawings, wherein FIGURE 1 is a somewhatschematic top view of the tube forming machine of the invention;

FIGURE 2 is a longitudinally sectional view taken along the line I-I ofFIGURE 1 and shows a part of the tube forming device of the invention;

FIGURE 3 is a cross sectional view taken along the line III-III ofFIGURE 2 of the tube forming device of the present invention;

FIGURE 4 is a cross sectional view taken along the line IVIV of FIGURE 2of the tube forming device of the invention;

FIGURE 5 is a schematic view of a control device for the adjustment ofthe relative distance of the rims of the metal sheet formed to a tube bythe apparatus of the invention;

FIGURE 6 is a somewhat schematic view of an adjustable support for themetal sheet at the welding point;

FIGURE 7 is a plan view of the support shown in FIGURE 6;

FIGURE 8 is a front view partly in section of an improved support;

FIGURE 9 is a plan view of the support shown in FIGURE 8.

Referring now to the drawings more in detail and turning first to FIGURE1, in which some of the known elements have been omitted for the sake ofclarity of the drawing, a metal sheet is decoiled from a supply drum andpasses over a train of planishing rolls (not shown) and is fed obliquelyinto the forming device 2 along the guide bars 3, 3' by a pair offeeding rolls 1, 1' which, in turn, are driven by the motor 5a via thereduction gear 5b. For the sake of clarity that part of the metal sheet1a which has not yet been introduced into the forming device 2 has beenomitted. The other, conventional and generally used elements are mountedon the machine frame 5 which can be turned around a pivot 6 in a mannerknown per se in order to modify the angle of introduction of the metalsheet into the forming device 2.

The forming device 2 with which the present invention is primarilyconcerned comprises a train of outer rolls 8.

The respective longitudinal axes of these outer rolls 8 are positionedupon an imaginary circle which is coaxial to the tube to be formed. Ascan be seen from FIGURES 3 and 4 this circle is not entirely closed. Therolls 8 thus form a sort of a jacket partly surrounding the tubularlybent metal sheets, which jacket is, however, interrupted since the rollsare not adjacent to each other, but are spaced, preferably equidistantlyfrom each other.

According to a preferred embodiment of the invention the forming device2 comprises, in addition to the train of outer rolls 8 a train ofinterior rolls 7, disposed in an analogous manner to the arrangement ofthe exterior rolls 8.

The angle defining the segment of the imaginary circle occupied by theexterior rolls is preferably greater than the angle defining the segmentof the imaginary circle occupied by the interior rolls.

However, the section of the imaginary circle upon which there arelocated, preferably equidistantly spaced, the respective centers of theinterior rolls 384 through 38-8 comprises preferably more than of a fullcircle.

The outer rolls 8 are positioned with one of their respective ends (inFIGURE 2 with their left ends) in a side plate 9, whereas the other endsof the rolls 8 are mounted in another side plate 10 located opposite tothe side plate 9. The side plates 9 and 10 form the upper part of themachine frame and are attached to the base plate 11 by braces 12 and 13.The base plate 11 is fixed on the ground by bolts 11a passing throughelongated slots 11b, so that the entire forming device can be moved inlongitudinal direction, ie in the directions in which the longitudinalaxis of the tube In formed of the metal sheet extends. The elevation ofthe forming device 2 can be varied relative to the guide bars 3, 3' byplacing suitable lifting and lowering devices underneath the base plate11.

The rolls of the exterior and the interior roller train are providedwith sleeves of which two are shown on the exterior roll 8 in FIGURE 2designated as 14 and 15. These sleeves are mounted adjacent to eachother and coaxially on the shafts for the rolls, such as the shaft 16. Aball bearing 42 can be provided between every pair of adjacent sleeves.

The shaft 16 of the roll 8 shown in FIGURE 2 ends on its respectiveopposite ends in a flat portion 17 and 18, respectively. Screws 19, 20turning in nuts 19a, 20a, and attached to the side plates 9 and 10 pressagainst these flat portions 17 and 18 of the shaft 16. The shaft 16(and, correspondingly, the other shafts of the rolls 8) has prolongedportions 21, and 22 at its left and right extreme end, respectively.These prolongations are guided in slots such as the slots 23 shown inFIGURE 4 provided in guide plates 24, 240, which, in turn, are fixed tothe side plates 9 and 10 by screws 26 and 27.

By means of this arrangement the exterior rolls can be displacedradially in regard to the longitudinal axis of the molding device 2.

The interior rolls forming the train of interior rolls 7 are arranged ina similar manner. However, they are not supported at their extreme endsin the identical manner. With their one end they are positioned in theside plate 9 attached to the side plate 9. There are also providedscrews, such as screws 28, 28a turning in nuts 29, 29a which are fixedto the side plate 9 and press against fiat end portions 30, 30a of theroll 7. Thus the interior rolls can be radially displaced just as theexterior rolls. The other ends of the interior rolls are positioned in aring 31 connected to the side plates 9, 9' by connecting rods 32, 33,34- which latter have threaded ends and are fixed to the side plates bynuts such as nut 35.

Furthermore, screws, such as nuts 36, 36a, are fixed to the ring 31 andreceive screws 37, 37a. The ends of these screws press against the flatportions of the shaft 38 of the interior roll. Guide plates 39, 39afixed by screws 40, 40a hold the shaft in its adjusted position. Theplates 39, 39a embrace their corresponding shaft 33 passing throughbores in these plates in the same manner as the plate 24 has beendescribed to receive the extreme end 21 of the shaft 16. Some of theshafts of the train of interior rolls can be prolonged beyond the sideplate 10 so as to give an additional support to the metal sheet. Inorder to avoid a rocking motion of the rolls in the ring support 31there are provided screws, such as the screw 41 opposite to the screw28.

It is also of advantage to provide collective adjustment means wherebythe adjusting screws for a train of rollers, for example the interiorrolls or the exterior rolls, as, for

instance, the screws 19, 20 and so forth are turned simultaneously. Thiscan be done, for example, by a transmission gear actuated by a commongear. This common gear operates all the adjusting screws disposed in oneplane. By coupling the transmission gears of the two side plates 9,lit), the rolls are made to approach or travel away from the metalsheets simultaneously. With other words, when adjusting the rolls withthese collective adjustment means, the axes of the rolls always remainin a parallel position relative to each other as well as relative to thelongitudinal axis of the tube formed of the metal sheet. The exactadjustment of the rolls relative to the metal sheet can be effected moreaccurately by graduated steps provided on the side plates.

It is of course also possible to provide every individual roll with anadjusting device common to two adjusting screws disposed at the twoopposite ends of the roll, as for example the adjusting screws 19 and20.

It is also advantageous to equip the collective adjustment means forsimultaneously displacing the rolls with coupling and decoupling meanswhich may be arranged, for example, between the common gear and thegears operating the screws so that every individual screw can bereadjusted before operating the several screws simultaneously.

The radial plane through the center of the rolls 7 divide into two equalangles the dihedral angles formed by the radial planes through thecenters of the outer rolls 8. Thus, each of three consecutive rolls,such as the three rolls 16-9, 38-8, 16-8, or the three rolls 16-8, 38-7,and 16-7, and so forth, form a complete bending device for the metalsheet passing therethrough.

In order to eliminate those unnecessary portions of the roll over whichthe metal sheet does not pass and to be able to use rolls of the samelength the side plates 9 and 10 can be replaced by warped plates withhelical contours. In this case the several exterior and interior rollsremain parallel to each other but their ends are progressivelylongitudinally displaced. For example, the roll 16-9 retains itsposition, the end of the roll 16-8 positioned in the side plate 9 isdisplaced in the direction of the plate It by a certain amount, theextreme end of the roll 16-7 positioned in the plate 9 is displaced inthe direction of the plate 10 by twice that amount and so forth, untilthe roll 16-1, the extreme end of which is positioned in the side plate9 is located approximately at the point A of FIGURE 2. The interiorrolls are to be arranged in an analogous manner.

The present invention also offers a number of further improvements ofknown elements in sheet bending devices. It has, for example, alreadybeen suggested to facilitate the formation of the tube by makingapproach one another the rims of the metal sheet at the welding point byexerting a pressure against the tube immediately after it has beenformed in the forming device and has left the same. The regulation ofthis pressure was to be effected by the operator attending to thewelding.

According to the present invention the comparatively coarse andinaccurate adjustment by an operator is replaced by an automaticcontrol. This automatic control can, for example, be effected by thedevice shown in FEGURE l and in FIGURE 5.

The formed tube In is pushed by the advancement of screw 91 which, inturn, is actuated by an electric motor 92 capable of forward and reversemotion. A return element consisting of "a piston 43 actuated by a spring44 mounted at the fixed machine frame tends to open the welding rim. Themotor running at forward speed tends to make the rims approach eachother. Between the rims as and 46 of the metal sheet to be welded (seeFIGURE 5) and a small distance from the welding point there are arrangedtwo friction disks 47 and 48 mounted at the end of a lever 49 and alever 50, respectively, fulcrumed at 51. The extreme end of the lever 49is fixed while the extreme end of the lever 50 forms another disk 53.This disk 53 is adapted to come into contact with two electricallyconducting strips 54 and 55 mounted together with the disk in thecircuit conditioning the change of operation of the motor. If the diskcontacts the strip 54, the motor 92 runs in a direction tending to pushapart the rims 4-5 and 46. If the disk 53 contacts the strip 55, themotor runs in opposite direction advancing the screw 91, thus tending topush the tube 1a and make the rim of the metal sheet approach at thepoint of welding. There can also be added a manually operated mechanismas, for example, the shaft 56 having a Cardan joint 57 and a hand wheel58. Instead of the screw and the electric motor it is also possible toprovide hydraulic or pneumatic adjusting means. Furthermore, theadjustment can be initiated by photoelectric cell means detecting thedistance between the rims and correspondingly actuating the motor in onedirection or the other as the situation may require.

The invention also provides an auxiliary device for the weldinginstallation. A support shoe 59 is disposed underneath the rims andapproximately perpendicular to the welding set. The support shoe 59 iscooled in a manner known per se by circulating water entering at 60 andleaving at 61. It is supported by a column slidingly arranged -in aboring of shaft 63 and fixed by screw 68. The shaft 63 bears a platform64 having longitudinal slots 71 and 72 receiving bolts 69 and 70 which,in turn, are mounted on a platform 65 supporting the platform 64. Byfastening the bolts 69 and '76 the two platforms are fixed relative toeach other but can be displaced in the range of the elongated slots '71,72. The movement of the column 62 permits to make the support shoe 59turn around the axis of column 62. The play of the bolts 69 and '70permits to modify the direction of a column 62 and the support shoe 59relative to vertical direction. Since the platform 65 mounted at the endof a two-armed lever 66 pivoted at 67 is actuated by a stretcher 68a itis possible to adjust the height of the support shoe 59. The positioningof the support shoe 59 is very simple and all the adjustments can belocated by graduated steps for abutments which facilitates the exactreplacement of the support shoe after it has been removed in order torenew its surface.

Since the width of the metal sheets varies, at least portions of thesurface of the support shoe may not be in perfect contact with the metalsheet and small defects of the welding may result therefrom. The contactbetween the support shoe and the metal sheet is improved according tothe invention by adding springs tending to push the support shoe againstthe metal sheet and by replacing the one piece support shoe 59 by anassembly of small support shoes forming a checkerboard and being pushedupwardly against the metal sheet separately. (See FIGURES 8 and 9). Byway of an example the FIGURES 8 and 9 show a steel support 81 and anumber of small support shoes of copper $2 gliding with a certain playin the bores 87 of the support -81. Each of these little copper shoeshas a groove 83 enclosing a fixed guide and detent pin 84 and is adaptedto be pushed upwardly against the metal sheet under the influence ofspring (35. The entire system can be cooled by circulating water passingthrough channels 86 in the steel support 81.

Advantages The bending device of the present invention is distinguishedfrom and greatly superior to known bending devices and particularlythose bending devices having a continuous forrm'ng jacket. In thepresent invention there is an interval from one roll to the next rolland from one bending device comprising three rolls to the next bendingdevice having another three rolls, In this interval no bending action isapplied to the metal sheet and, consequently, the internal tensions inthe sheet are allowed to be evenly distributed without intervention fromexternal forces. Furthermore, each of the rolls is provided with aplurality of adjacent sleeves constituting independent, coaxialrevolving elements and allowing for a certain longitudinal play of themetal sheet facilitated by the provision of ball bearings between theadjacent sleeves. This longitudinal play also favors the elimination ofelastic tensions and contributes to the uniform distribution of theinternal tensions of the metal sheet.

Due to the means for radially adjusting the interior and exterior rollsrelative to the central longitudinal axis of the tube, the formingdevice of the present invention can be adapted to produce tubes or pipesof different diameters.

Furthermore, the individual rolls and hence the groups of three rollseach constituting one of a succession of bending devices are adjustableindependently from each other. Consequently, a very exact bending ismade possible by the forming device of the present invention.

The automatic adjustment means for the rims of the metal tube to bewelded together is more accurate and reliable than the manual adjustmentperformed by an operator. Defects in the welding together of the rimsare thus avoided and a firm and accurate mutual attachment of the rimsis facilitated.

The improved support means of the invention auxiliary to the weldinginstallation are extremely mobile and can be displaced in threeditierent directions, thereby greatly facilitating the weldingoperation.

Furthermore, the composite support means comprising a number of smallsupport shoes affords a more perfect adjustment of the support to unevenmetal sheets of varying widths and ensures a better contact between thesurface of the support and the metal sheet, thus contributing to a moreperfect welding.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

What I claim is:

1. A tube manufacturing machine of the type helically coiling a strip ofsheet metal and attaching the adjacent rims of the coiled sheet to eachother, having a tube forming device into which the strip of sheet metalis introduced and wherein it is tubularly bent, said device comprising aplurality of rotatable exterior rollers and a plurality of rotatableinterior rollers, said exterior rollers being arranged with theirrespective longitudinal axes upon a segment greater than 180 of animaginary circle at a predetermined distance from each other, with saidlongitudinal axes of said rollers being parallel to that of the tubebeing formed, said exterior rollers externally surrounding at leastpartly the metal sheet, said interior rollers being arranged oppositethe interval between two neighboring rollers of said exterior rollers,and said interior rollers being with their respective longitudinal axesupon a segment of another imaginary circle at a predetermined angulardistance from each other and at the inner side of the metal sheet, allof said rollers being mounted for movement toward and away from the axisof the tube being formed, and means for feeding a strip of metal betweenthe exterior and interior rollers at an acute angle to the axis of therollers and the tube being formed to form a helical tube, whereby tubesof different diameters may be produced by the same machine.

2. A tube manufacturing machine of the type helically coiling a strip ofsheet metal and attaching the adjacent rims of the coiled sheet to eachother, having a tube forming device into which the strip of sheet metalis introduced and wherein it is tubularly bent, said device comprising aplurality of rotatable exterior rollers and a plurality of rotatableinterior rollers, said exterior rollers being arranged with theirrespective longitudinal axes upon a segment greater than of an imaginarycircle at a predetermined distance from each other, with saidlongitudinal axes of said rollers being parallel to that of the tubebeing formed, said exterior rollers externally surrounding at leastpartly the metal sheet, said interior rollers being arranged oppositethe center of the interval between two neighboring rollers of saidexterior rollers, every three of those neighboring of said exterior andinterior rollers forming a triangle thus constituting an independentbending device, and said interior rollers being with their respectivelongitudinal axes upon a segment of another imaginary circle at apredetermined angular distance from each other and at the inner side ofthe metal sheet, all of said rollers being mounted for move- ,menttoward and away from the axis of the tube being iformed, and means forfeeding a strip of metal between the exterior and interior rollers at anacute angle to the axis of the rollers and the tube being formed to forma helical tube, whereby tubes of difierent diameters may be produced bythe same machine.

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